The present invention relates to a multi- and full-color thermosensitive recording method, and more particularly to a multi- and full-color thermosensitive recording method of forming colored images on a thermosensitive recording sheet capable of forming two to four different colors thereon by application of different quantities of thermal energy thereto.
Recently a thermosensitive recording method of recording images on a thermosensitive recording material in a mono-color by utilizing chemical or physical changes of thermosensitive materials upon application of thermal energy is widely used, not only for copying books and documents, but also in the printers for recording output information from measuring instruments and computers, facsimile, automatic ticket vendors, and in label printers of POS systems. This wide application of the thermosensitive recording method is due to the advantages over other conventional recording methods that no noise is generated during recording and image development and fixing steps are unnecessary.
Further, there is a great demand for multi- or full-color recording of the output information in accordance with the recent popularization of personal computers and development of information transmission systems. As a matter of course, research and development activities for developing recording materials and methods capable of attaining multi- or full-color recording are conducted.
As recording methods capable of attaining such multi- and full-color recording, for example, ink-jet recording method, thermosensitive recording method, electrostatic recording method, electrophotographic recording method and silver halide photographic recording method are known. Of these methods, research and development of the thermosensitive recording method are most actively performed because of the advantage over other methods that the mechanical maintenance is extremely easy in addition to the previously mentioned advantages of the thermosensitive recording method
As thermosensitive recording methods capable of performing multi- or full-color recording, a wax thermal image transfer method, a reaction-type thermal image transfer method and a sublimation-type thermal image transfer method are known. These thermal image transfer methods, however, have the shortcomings that two sheets, that is, an image transfer sheet and an image acceptor sheet, are necessary and a different image transfer sheet is also necessary for each color formation for multi- or full-color recording, so that the recording process is extremely complicated.